The present invention relates to a myocardial revascularization device and method for making channels in the inside of the heart ventricle to perfuse the myocardium.
Within this application several publications are references by arabic numerals within parentheses. Full citations for these and other references may be found at the end of the specification immediately preceding the claims. The disclosures of all of these publications in their entireties are hereby incorporated by reference into this application in order to more fully describe the state of the art to which this invention pertains.
It is well known that coronary artery disease is a pervasive disease afflicting many people in this country. Many of these people are treatable by coronary artery bypass surgery. However, alternative methods of myocardial revascularization are required for patients with coronary artery disease not amenable to coronary artery bypass. Investigators have used the CO2 laser in arrested hearts to create transmural channels from the epicardial surface. The channels increase cardiac perfusion by shunting blood from the ventricle to myocardial sinusoids, and can endothelialize and remain patent indefinitely. In this approach, the energy is delivered from outside the ventricle, and the channels formed by the laser energy penetrate the full thickness through the ventricular wall.
It is an object of the present invention to provide an apparatus and method for myocardial revascularization to increase blood flow to the myocardium from the endocardium without using the native diseased coronary arteries.
It is an object of the present invention to provide an apparatus and method for myocardial revascularization to be used with patients having extensive coronary atherosclerosis in whom bypass surgery is not possible.
It is an object of the present invention to provide an apparatus and method for myocardial revascularization which avoids forming channels which penetrate the full thickness through the ventricular wall.
The present invention provides a method for cardiac revascularization using a transendocardial approach with an energy source such as a thulium-holmium-chromium: YAG (THC-YAG) laser. This approach can be used on a beating heart, concentrates its effects on the endocardium, which is the surface at highest risk for ischemia, and reduces potential risk of bleeding and aneurysmal formation associated with transmural channels.
According to one aspect of the invention, a method for myocardial revascularization of the heart in a patient is provided, comprising positioning a channel forming energy emitter inside the ventricle of the heart, and directing energy from the channel forming energy emitter toward the ventricular wall in an amount sufficient to form at least one channel in the ventricular wall into the myocardium to thereby increase blood flow from the endocardium to the myocardium.
Which identifies the location of the emitted energy from the channel forming energy emitter, locating an aiming beam energy detector outside the heart at a position adjacent a desired channel forming site, and wherein the step of directing energy from the channel forming energy emitter is performed after the aiming beam energy detector detects aiming beam energy to thereby indicate that the channel forming energy emitter is directed to the desired channel forming site. The desired channel forming site may be based on familiar epicardial anatomic landmarks, such as the epicardial branches of the coronary arteries.
According to another aspect, the present invention provides a method for myocardial revascularization of the heart in a patient, comprising entering the ventricle of the heart with a catheter having a lumen which houses a fiber which emits energy at a fiber end, locating the fiber end proximate to the ventricular wall, and emitting energy from said fiber end in an amount sufficient to form a channel in the ventricular wall into the myocardium to thereby increase myocardial blood flow from the endocardium to the myocardium.
A myocardial revascularization device is also provided in accordance with the invention, comprising a handpiece having at least one lumen, and having an insertable end and a handling end, a fiber for carrying energy from an energy source to a fiber end from which the energy is emitted, said fiber being received in one of said lumens, means for moving the fiber within the lumen to different stop positions, whereby the fiber end extends from the handpiece insertable end at different sites of a ventricular wall corresponding to said stop positions, and means for transmitting energy to said fiber end in an amount sufficient to form a channel in the ventricular wall into the myocardium at each of said sites, to thereby increase myocardial blood flow from the endocardium to the myocardium.
The present invention also provides a myocardial revascularization device, comprising a channel forming energy emitter means, for insertion into the ventricle cavity of a heart, for emitting energy to form at least one channel in the ventricular wall into the myocardium, an aiming beam energy emitter means for emitting an aiming beam which identifies the location of energy emitted from the channel forming energy emitter means, an aiming beam energy detector, for placing against the exterior of the heart, for detecting an aiming beam from the aiming beam energy emitter means, and means for energizing the channel forming energy emitter means in response to detection of an aiming beam by the aiming beam energy emitter. The aiming beam energy detector location may be selected on the basis of familiar epicardial anatomic landmarks, those being the epicardial branches of the coronary arteries.
These and other advantages will become apparent from the detailed description accompanying claims and attached drawing figures.